Therapeutic silica compounds and method of making the same



Patented Aug. 1, 1933 7 UNITED sir-Ares THERAPEUTIC SILICA COMPOUNDS AND METHOD OF MAKING THE SAME Rudolf Zellmann, Badebeul near Dresden, Germany, assignor to Chemische Fabrilr von Heyden, A. G., Radebeul near Dresden, Germany, a Corporation of Germany No Drawing; Continuation of application Serial No. 327,197, December 19, 1928, and in Germany February 18, 1925. This application December 19, 1928. Serial No. 327,196

This application is a continuation of'my contemporaneouslyfiled application 327,197 relating to therapeutically highly effective silica compounds, such as obtained by coating silica-gel, obtained in any of the well known ways, with a metal, or a salt of the same difliculty soluble in water.

= In this appication I shall describe how I operate to make similar therapeutically highly effective silica compounds by acting upon-a colloidal solution of silica, obtained in any of. the well known ways, with colloidal substances, such as a colloidal metal, a colloidal metalloid, or a colloidal metal salt.

In the following examples I shall describe a very simple method of how I may obtain my new therapeutically highlyeffective silica compounds. In-preparing the same Imay start from colloidal silica solution as obtained for instance by dialysis.

If one mixes such a colloidal silica solution with a solution of silver nitrate and adds then'sodium chloride solution or hydrochloric acid, then one obtains a colloidal solution of silver-chloride. If this solution is evaporated in a fiat pan, opaque laminations are obtained which upon investigation under the microscope prove optically entirely homogeneous so that it appears that the silver- I In a similar manner I may incorporate a metal-.

loid, such as sulfur, into the colloidal silica solution. 1 i

The new colloidal compounds may be obtained in dry state by drying or evaporating at ordinary i 5 or at reduced pressure.

In the operation of my invention I proceed about as described in the following examples:

Example 1 I mix 5 liters of a 3.5% colloidal solution of silica with 50cc of a 1% colloidal gold solution.

Upon evaporating the solution mixture one obtains laminations of glass-like appearance and of a reddish violet color.

Example 2 Example 3 I admit into a colloidal solution of silica some sulfur dioxide in the form of its aqueous solution and introduce then hydrogen-sulfide into the mixture, whereupon the solution is evaporated.

Instead of operating thus, I may add a solution of sulfur, obtained by the reaction of H28 upon $02, into thecolloidal silica solution'and otherwise proceed as described sub 1-3.

Example 4 Instead of starting from pure-solutions of colloidal silica as obtained by dialysis one can also use crude solutions as obtained by mixing waterglass with acids. For instance liters of diluted hydrochloric acid of 'about 6.7" 36-. are mixed with 125 liters of an aqueous solution containing 45 liters of waterglass of 36-38 B. To this mixture a solution of 0.5 kg. arabic' gum in 5 liters of water is added. Now the mass is well agitated and a solution of 110 g. silver-nitrate in 5 liters of water is added. After 3,days the mixture has become a gelatine-like niass, which is washed with water, pressed oif, dried and pulverized.

' Silica-gel containing silver instead of silverchloride is made in a similar way by adding a reducing agent in order to transform the silversalt into metallic silver. From the .description of the physical properties of the products obtained by the operation of the Examples 1 to 4, inclusive, it is obvious that the colloidal metal, or metal compound, or sulfur; is actually dissolved in the silicic acid. I want to emphasize specifically that the products are not merely mixtures of themetals with silicic acid, or merely adhere to the surface of the silicic acid. As already stated,'they are more than that; for instance, the product obtained by Example 1, consistingof colloidal silicic acid and colloidal gold,

represents a genuine. solutionof gold. Even if examined-under a microscope of the highestpower one cannot detect any solid particles of gold because the. product is an absolutely homogeneous mass; it has the nature of a glass, for

gold dissolved in its body similarly to the well known rubin-glasses.

In conformance with the physical form of the product of my invention the same may be used both externally and internally; in the form of laminations it may very advantageously be used for the disinfection of any external wounds and in the form of powder, for instance, if produced by Example 4;, it may be used externally as a dusting powder for the disinfection of wounds or it may be used internally for the disinfection of the intestines.

What I claim is:

'1. The method of preparing solid therapeutically effective compounds, said method comprisihg mixing an aqueous solution of a colloidal inorganic substance selected from a group consisting of colloidal metals and of colloidal metal salts with an aqueous solution of silica sol and evaporating the homogeneous mixture to dryness.

2. The method of preparing solid therapeutically-effective compounds, said method comprising mixing an aqueous solution of colloidal silver with an aqueous solution of silica sol and evaporating the homogeneous mixture to dryness.

3. Themethod of preparing solid therapeutically eifective compounds, said method comprising mixing an aqueous solution of colloidal silver chloride with an aqueous solution of silica sol and evaporating the homogeneous mixture to dryness.

4. As a new articleof manufacture, a therapeutically effective silica compound in solid form, consisting of a dry residue of a homogeneous mixture of an aqueous solution of an inorganic substance, selected from a group consisting of colloidal metals and colloidal metal salts, with an aqueous solution of silica sol.

5. As a new article of manufacture, a therapeutically efiective silica compound in solid form, consisting of the dry residue of a homogeneous mixture of an aqueous solution of colloidal silver with an aqueous solution of silica sol. 6. As a new article of manufacture, a therapeutically effective silica compound in solid form, consisting of the dry residue of a homogeneous mixture of an aqueous solution of colloidal silver chloride with an aqueous solution of silica sol.

RUDOLF ZELLMANN. 

